Kamole Weir
The Kamole is the largest water treatment facility on Maui. Treated water from the facility goes to 6,687 services and can supply water to almost the entire region, or 9,865 services, if necessary. The facility is the primary source of water for nearly all of Upcountry during times of drought.

Piiholo
This facility was built to meet regulatory requirements and improve Lower Kula's water quality. Piiholo is located in the Makawao Forest Reserve adjacent to the Piiholo Reservoir. It uses direct filtration to treat its water and uses chlorine as a disinfectant.

Olinda
The water that supplies the Olinda comes from the Waikamoi Rain Forest, and is stored in the Waikamoi and Kahakapao Reservoirs. These reservoirs will also supply the non-potable agricultural line currently under construction.

Lahaina
This facility is located above Lahainaluna High School. The Lahaina WTF was completed in June 1997 at a cost of about $10 million. The Lahaina facility utilizes microfiltration to treat surface water and chlorine to disinfect it after treatment.

Mahinahina
The Mahinahina is located near the Kapalua airport and draws from three primary sources of raw surface water. Mahinahina utilizes pre-sedimentation to treat raw surface water. Rapid mix, flocculation, and direct filtration with a mixed media filter are used. After this process, chlorine is added for disinfection.